A lot of harbor cities are rethinking their approach. Many of the areas at the harbors are close to the city center and are currently being released for the urban planning. Especially fallow zones at the harbor and waterside are being newly designed for their utilization and are integrated into the latest urban planning political issues. Therefore, the transformation processes are opening a great chance to reactivate those areas, that have been used suboptimal until now. Consequently, worldwide, disused harbors that are located close to the city center are being seen as an alternative to the settlement extensions onto urban public green space. Thus these areas are being redesigned. The conversion of the zones at the harbor and watersides makes it possible to revitalize these areas, that have been used for port handling in the past. Not only the city and the harbor are being reunited again but also water and land as well as the history, the present and the future. Urban development projects are increasingly focused in relation to urban development due to the increasing importance of the urban water fronts. At the same time urban waterbodies and urban spaces close to the water pose different challenges and risks, that have to be managed. Those challenges can be structural or water economic but can also be related to topics like environment, climate or the preservation of open spaces. Although this focus is similar in many harbor cities, the cities deal with these topics differently concerning the planning, the goals and also the dimensioning. Therefore, the aim of this diploma thesis is to illustrate the transformation process of different harbor areas. In the beginning the topic of urban development close to the water will be presented. The change of the image and the historical stages as well as the role of the urban development and the handling with waterfronts will be analyzed. In the main part some explanatory approaches concerning the fallow areas and the revitalizing are illustrated. Also todays status and the experiences of transforming the harbor areas are presented on the basis of three example cases. These example cases consist of the cities Hamburg, Kopenhagen and Rotterdam. On the basis of these three cities it can be demonstrated, how they have been used the transformation of the harbor zones. Additionally, the parallels as well as the differences between their initial situation and their claims of utilization are being presented in order to conclude with analyzing whether the town planning resulted in a successful transformation and reprogramming of fallow areas with identity-establishing features.